Holiday clothes for a short fat forty something

I'm really struggling to find things to take on holiday this year. We are going to a typical beach resort in the summer and what to wear on an evening is really bugging me.

I'm 43 years old, a size 16 and only 5'2 so I always look frumpy in cropped trousers, I've got flabby arms so don't like vest tops. Last year when we went the resort was full of young slim things in skater and bodycon dresses and towering heels.

I feel frumpy in dresses as I've not got good legs for short ones and long ones make me look huge. Shorts look ridiculous too.

I'm stuck, what should I wear out in the evenings without looking overdressed but is cool, comfy and not frumpy.